Firefox Tip: Undo Accidental Tab Close
If you have accidentally closed a tab (or several tabs) with FireFox and would like to revisit the site (or all the sites) that were accidentally closed, simply use Add New Tab and add a blank tab…
Right click on the tab control bar and select Undo Close Tab. Rinse and repeat for however many tabs your accidentally closed.
The keyboard shortcut to perform this undo is Control-Shift-T.
